function abrirPag(valor){
	var url = valor;
		
	xmlRequest.open('GET',url,true);
	xmlRequest.onreadystatechange = mudancaEstado;
	xmlRequest.send(null);

	if (xmlRequest.readyState == 1) {
		document.getElementById('conteudo').innerHTML = '';
	}
	return url;
}

function mudancaEstado(){
	if (xmlRequest.readyState == 4){
		document.getElementById('conteudo').innerHTML = xmlRequest.responseText;
	}
}